John Herschel discovered NGC 3393 = h3299 on 24 Mar 1835 and recorded "F; S; R; precedes two bright stars." His position (3 sweeps) matches ESO 501-100.

400/500mm - 18" (3/13/04): faint, fairly small, elongated 2:1 NNW-SSE, 0.8'x0.4'. Contains a small, round, bright nucleus. The galaxy precedes two mag 9 (HD 93674) and 11 stars 2.9' E and 1.6' E (nearly equally spaced with galaxy). This observation (made through thin clouds) refers to the brighter core region and I probably missed the large, low surface brightness halo. Outlying member of AGC 1060 (Hydra I), located 3.5 degrees northeast of the core.

Notes by Steve Gottlieb